Risk Factors for Operative Adjacent Segment Disease Following Laminectomy Without Fusion for Lumbar Spinal Stenosis

Area of Science:

• Spine surgery outcomes
• Degenerative spinal conditions
• Biomechanics of the spine

Background:

• Adjacent segment disease (ASD) is a known complication following spinal fusion surgery.
• It is often attributed to altered spinal biomechanics after fusion.
• However, ASD may also be a natural consequence of aging and prior surgical history.

Purpose of the Study:

• To determine the incidence of ASD in patients who underwent lumbar laminectomy without fusion.
• To identify risk factors associated with ASD development after non-fusion lumbar surgery.

Main Methods:

• Retrospective analysis of adult patients undergoing open laminectomy for lumbar stenosis over a 6-year period.
• Exclusion criteria included fusion, diskectomy, >4 level procedures, or pre-existing adjacent fusion.
• Primary endpoint: incidence of ASD requiring reoperation; Secondary endpoint: risk factor identification using multivariate Cox proportional hazards model.

Main Results:

• 658 patients were included in the analysis.
• The incidence of ASD requiring reoperation was 9.4% (62 patients) over a mean follow-up of 32 months.
• Prior history of cervical/thoracic spine surgery, lumbar spine surgery, or joint arthroplasty were significant risk factors for ASD.

Conclusions:

• Nearly 10% of patients developed adjacent segment disease (ASD) after lumbar laminectomy without fusion.
• This suggests that the natural degenerative process and prior surgical history contribute to ASD.
• Further research is needed to quantify the specific impact of fusion on ASD acceleration.